dotwhat.net

[Blizzard]

Did it ever happen to you? You've just downloaded a file and it has an extension you've never seen before? Here is your solution!

http://www.dotwhat.net/

This site has a big archive on different extensions. If you ever need to know "What extension THAT FOR?!", just visit this site and find it out!

[Moss.]

I've always used FileXt.

[Arrow]

.what? .net.

http://www.dotwhat.net/list_s/extension_sex/id_2575/